Many types of high-pressure couplings are known. One such type is described in U.S. Pat. No. 5,553,895, titled “Coupling Assembly” by Karl et al. A partial cross-section of the assembly is shown in FIG. 1, including a male member 101, a female member 103, a split locking ring 105, a release sleeve 107, and a release tool 109. During its locked condition, the locking ring 105 is trapped between a conical surface 111 of the male member 101 and a chamfer 113 of the female member 103, preventing the male member 101 from being separated from the female member 103. In order to separate the parts 101 and 103, the locking ring 105 must be dislodged into a chamber 115. By inserting the release tool 109 downward between the release sleeve 107 and a flange of the male member 101, force is imparted on the release sleeve 107 in a direction toward the locking ring 105, which moves up the conical surface and into the chamber 115, thereby allowing the male member 101 to be separated from the female member 103. When the coupling is separated, the locking ring 105 remains engaged within the female member 103 and the release sleeve 107 remains on the male member 101.
When the parts 101 and 103 do not separate after the desired vertical insertion of the tool 109, one tends to try to pry the tool 109 horizontally between the release sleeve 107 and the flange of the male member 101 by leveraging off the male member 101 to impart a horizontal force on the release sleeve 107. Unfortunately, such prying is likely to fail because the horizontal force pushes the sleeve 107 horizontally into the ring 105 that is against the conical surface 111, which is part of the male member 101. Lever action applied to the pry tool 109 is a force exerted on the release sleeve 107 in the correct direction as intended to release dislodge the ring 105, but an equal but opposite force is applied to the male member 101, causing the male member's conical surface 111 to move to the right, thereby wedging the ring between the conical surface 111 of the male member 101 and the chamfer 113 of the female member 103. Because there is not a sufficient opening between the conical surface 111 and the chamfer 113 when the ring 105 is wedged, the ring 105 is unable to be dislodged into the chamber 115. Such leverage action or prying does not help to release the ring 105.
Accordingly, there is a need for a more reliable way to separate the parts of such a coupling.